The current study will determine the insulin sensitivity of a subset of the Epidemiology of Diabetes Complications (EDC) study population. A subgroup of 24 EDC participants will be selected based on their risk of having insulin resistance. Two tests will be performed on this subset, an insulin clamp and a CT scan. Analyses will determine if a proxy measure can be utilized to estimate the risk of having insulin resistance in an IDDM population and the relationship insulin sensitivity has on the development of complications, especially macrovascular.